This invention relates to the utilization of solar energy and particularly to a system for heating liquid by means of solar energy.
This invention pertains to the type of solar utilization system wherein a heat exchange fluid is circulated through an absorber panel located within an enclosure which has a transparent cover. Radiant solar energy is absorbed by the absorber panel and the heat so generated is carried away by the heat exchange fluid. Convective heat losses are averted by the enclosure which provides the so-called "greenhouse effect."
A customary practice in this field has been to provide preassembled units, each having a housing which serves as the enclosure and contains insulation material, an absorber panel and a transparent cover. When an array of such units is mounted on a roof or other appropriate inclined support surface, the individual units are customarily connected together by headers which lie outside the frames and are connected to an appropriate circulatory system. The construction of the individual units, their installation on a support surface and their connection to a header structure is time consuming and expensive. Perhaps more importantly, it is wasteful of the area occupied by the array since a substantial area is devoted to the frame members located within the perimeter of the array and to the header structures which most often are connected to the exterior of the frames and contribute nothing to the solar absorptive surface of the system.
The present invention is directed to a system including a novel absorber panel, a novel collector assembly and a novel method of installation. Various aspects of the invention serve individually and jointly to provide a number of advantages, presenting a highly effective system at a relatively modest expense. In some respects, the system permits and pertains to individual components which are simple and relatively inexpensive to manufacture. In another respect, the system may be installed at minimum expense on new or existing structures. Plumbing tools and techniques are not required, and installation is quick and easy.
Furthermore, the system of the invention is quite effective in operation and entails a minimum of maintenance attention due to the various structural and procedural features described herein. For example, frame elements are eliminated from within the perimeter of the array to optimize the available effective absorber surface area and avoid the loss of heat produced by the presence of the internal frame members. The main headers are preferably placed within the collector enclosure so that the header surface itself is also subjected to the incident solar energy and to the high temperatures within the enclosure. Adjacent absorber panels are overlapped so that substantially all of the area within the enclosure serves as an effective absorber surface.
In one respect, the invention pertains to a solar collector assembly having a plurality of absorber panels each being provided with a header. Means are provided for circulating fluid through the headers at subatmospheric pressure, and the headers are interconnected by resilient sleeves having their opposite ends telescoped over the headers whereby subatmospheric pressure biases the sleeves into sealing engagement with the headers.
Another inventive concept relates to a solar collector assembly having a pair of solar absorber panels located beneath a cover which is transmissive of solar radiant energy. The marginal portions of the absorber panels overlap and are provided with spaced-apart lateral recesses which provide openings through which upwardly-extending cover support brackets extend.
Another novel concept of the invention is that of placing a plurality of absorber panels within a single enclosure which has a cover transmissive of radiant solar energy, the adjacent marginal portions of the absorber panels being overlapped and slidable relative to each other to permit thermal expansion thereof.
Further, the invention pertains to a solar collector assembly in which a hanger bracket projecting upwardly from the support surface engages the absorber panel to prevent downward slipping movement of the panel. The enclosure is attached to the support surface independently of the hanger bracket and absorber panel assembly, whereby the unit is easily installed and capable of sustaining substantial relative movement due to thermal expansion.
The invention also concerns a solar absorber panel structure in which a pair of substantially parallel plates are sealed together, and one of the plates is deformed to provide a raised integral header therein. An external header is spaced from the integral header and is mechanically connected to the plates; and, a fluid connector provides a fluid passage between the external header and the raised integral header.
The installation method according to the invention involves the initial attachment of a plurality of upstanding hanger brackets to an inclined support surface, and placement of thermal insulation material on the support surface and on the upstanding hanger brackets so that the insulation material is prevented from slipping downwardly. An absorber panel assembly is placed on the insulation material and engaged with the hanger brackets to prevent the absorber panel assembly from slipping downwardly. The absorber panel assembly is then enclosed by placing thereover a cover which is transmissive of radiant solar energy.
These various inventive concepts will be understood more completely from a study of the accompanying drawings and description thereof. This specification describes only a preferred embodiment which possesses all of the claimed inventive features, but it is to be understood that these concepts may be used independently of each other in a wide variety of structures to enjoy the benefits of this invention.